1. An ecologist is studying the proportion of wild giant pandas that survive to adulthood (6 years old) in a certain forest. He randomly samples 40 infant pandas over a 10 year period and follows them each for 6 years. He finds 28 infants survive to at least 6 years old. You can assume the sample is representative.

(a)Calculate and interpret a 90% Wald confidence interval for the proportion of wild giant pandas that survive to adulthood. Define any symbols you use and specify any/all conditions needed to solve the problem.

(b) An old ecological study claims that about 54% of all pandas survive to adult hood. Is this value plausible based on the interval constructed using the ecologist's sample in part a)? Why/Why not?

2.The gross annual salary for those who work at least 40 hours per week in Pittsburgh is right-skewed with a mean of $66,000 and a standard deviation of $16,000.

(a)A random sample of 10 of these workers (who work at least 40 hours per week) was taken. What can you say about the distribution (shape, center, and spread) of the average salary for the sampled workers?

(b)A worker (who works at least 40 hours per week) is randomly chosen. What is the probability that the person makes over $50,000?

(c)How does the variability in individual salary compare to the variability in the average salary for samples of size n > 1 and why?

3.Is the dominant hand stronger than the non-dominant hand? We can measure the strength of someone's grip using a hand dynamometer. This device measures the grip strength in Newtons (N). We can use this device to compare the strength of the dominant and non-dominant hand. (You can assume that the population of differences in hand strengths is normally distributed, and that this is a random sample of participants.)

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